Four-parameter Taylor series based light-emitting-diode model

This paper presents a light-emitting-diode (LED) model based on the four-parameter Taylor series to describe the V-I characteristic of the LED at different junction temperatures. Therefore, in order to precisely model the LED non-linear characteristics at different junction temperatures, an improved Taylor series based LED model is proposed according to the four available parameters: maximum operating point, rated operating point, knee point, and temperature coefficient obtained from LED V-I curves. Furthermore, in order to perform the DC and small-signal simulation and analyses of LED drivers at different junction temperatures, the proposed model can be used to derive the LED DC and small-signal equivalent resistances at different junction temperatures. Finally, the measured results are compared with the modeled V-I curves, DC equivalent resistances, and small-signal equivalent resistances of the experimental LED at different junction temperatures.